Automatic rerecording system



Aug. 5, 1953V c. N. SHIPMAN AUTOMATIC RERECORDING SYSTEM Filed Dec. 31,1956 Ill-.lilo mwa MN. NN m. QN M Nk.. Nw?

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INVENTOR. 2217! N J'ipmp BY ATTORNEY United States AUTOMATIC RERECORDING SYSTEM Carl N. Shipman, Rivera, Calif., assignor to Radio Corporationof America, a corporation of Delaware Application December 31, 1956,Serial No. 631,683

11 Claims. (Cl. 179-1001) This invention relates to sound recordingsystems, and particularly to an automatic rerecording system whereby anymanual adjustments of amplitude levels or other characteristics of asignal may be repeated automatically while permitting additional manualadjustments.

In Wolfe Patent No. 2,279,018 of April 7, 1942, an automatic soundrerecording system is disclosed and claimed, the Wolfe system utilizingvariable gain amplitiers, a magnetic recorder for the control tracks anda mixing panel which varies the level of gain control frequenciesapplied to the variable gain amplifiers. The present invention is asimplication of the Wolfe system since it utilizes normal, standardaudio signal attenuators, two attenuators being connected in series, oneof which is adapted to be motor actuated from a control track Q and theother of which is adapted to be manually activated. The control tracksignal may be recorded on a rst control track iilm and then recorded ona second control track film during a subsequent rehearsal. Also, asingle ilm having both control tracks instead of audio tracks thereonmay be used, as disclosed and claimed in Bradbury Patent No. 2,733,301of January 3l, 1956. By connecting two standard potentiometers inseries, the potentiometers being on the attenuator shafts, and settingthe motor controlled attenuator to its central or other fixed positionduring the actuation of the manual attenuator, and then setting themanual attenuator to the central or other fixed position during asubsequent reproduction, the proper amplitude or level control of thelsignal is obtained.

The principal object of the invention, therefore, is to provide animproved, automatic rerecording system by means of which the control ofvarious signal character- :istics is facilitated.

Another object of the invention is to provide an improved system forautomatically repeating a rerecording operation.

A further object of the invention is to provide an improved system forduplicating the variations made in the transmission of electricalcurrents and to enable the making of manual changes during theduplication and re-transmission of the currents.

A still further object of the invention is to provide an improvedrerecording system which is under the simultaneous control of both acontrol track and manual operation.

A better understanding of this invention may be had from the followingdetailed description when read in connection with the accompanyingdrawing in which the single figure is a combination diagrammatic andblock diagram of a rerecording system embodying the invention.

Referring, now, to the drawing, the signal to be rerecorded is on a lilm5 which is shown as a magnetic lilm detected by a magnetic reproducehead 6. Although magnetic film is illustrated as the source of the audiosignals, it is to be understood that the sound tracks to be rerecordedmay also be on photographic iilm. In the present drawing, the magnetichead is connected over a conductor 7 to a standard attenuator 8, thisattenuator being of the type now used in manual-operated rerecordingsystems. The attenuator 8 is connected over conductor 10 to a secondstandard attenuator 11, the output of which is fed over conductor 12 toa mixing network 13, then to an amplifier 14 and a recorder 15 whenswitch 52 is closed. The mixing network 13 may be fed from other similarchannels as indicated by the conductors 17, two such audio sources beingshown by films and 21 with respective magnetic reproduce heads 22 and23. A monitor 18 is connected to the mixing network 13.

The standard attenuator 8 has mounted on one end of its shaft a motorunit 26 which may be either A. C. or D. C. depending on the type ofcontrol signal being used. The other end of the shaft 25 has connectedthereto a potentiometer including a resistance element 28 and a slidei29, rotation of the shaft 25 varying the voltage between the ends of theresistor 28.

The standard attenuator 11 has mounted on its shaft 30 a knurled handknob 31 of the type now being used with rerecording attenuators, and onthe other end of its shaft a potentiometer 34 having a resistor element32 and a slider 33. Thus, any changes made in the attenuators 8 and 11will be followed by the respective sliders 29 and 33. The twopotentiometers 27 and 34 are connected in series with an A. C. or D. C.voltage source over conductors 35 and 36 and a resistor 37. Alsoconnected in parallel with the resistor elements 23 and 32 is arecording amplier 39 which is supplied with bias current from an erasea'nd bias oscillator 40.

The output of the recording amplier 39 is fed to a swinger 41 of aswitch 42, while a second output from the oscillator is fed to a swinger43 of the switch 42. A third swinger 45 is mechanically connected to theswingers 41 and 43 as indicated by the dotted lines 44, all threeswingers being operable by either a relay 46 or manually. With theswinger 41 in its upper position, the output of the recording amplifier39 is fed to a magnetic record-reproduce head 47, while the output ofthe oscillator 4t) is fed over conductor 4S to a magnetic erase head 49.The heads 47 and 49 are associated with the magnetic control track lmSi).

During a iirst rehearsal, the motor driven attenuator E5 is adjusted andmechanically or otherwise held so that the slider 29 is and remains atits central or other xed position on the resistor 2S. Thus, theamplitude of the output of the reproduce head 6 is varied by the manualoperation of the knob 31 controlling the attenuator 11 and thepotentiometer 34. As the slider 33 is moved over its resistor element32, voltage variations of the A. C. or D. C. source will be recorded byrecordreproduce head 47 on control track lm Sil, this voltage varyingaccording to the manual adjustments of attenuator 11. Simultaneously,erase current is applied to erase head 49 to insure a clean recordingarea. During this rehearsal, switch 52 is open so that no recording ismade of the rehearsal run while switch 53 is closed.

T o automatically repeat the adjustments made by attenuator 11, theslider 33 of potentiometer 34 is set at its central or other fixedposition to provide the same attenuation introduced previously byattenuator 8 when attenuator 8 was held ixed. During this operation, theswitch 42 is thrown to its second or lower position. In the secondposition of switch 42, swinger 41 connects the output of the recordingamplifier 39 over conductor 54 to a record-reproduce head 5S.Simultaneously, the swinger 43 connects the output of the oscillator 40over conductor 56 to erase head 57, erase head 57 and record- 'aafe'nieaAug. s, 195sv reproduce head `55 being associated with the second conitrol track film 58. Swinger 45 in its second position connects theoutput of record-reproduce head 47 over conductors 6i? and 61 to acontrol signal amplifier 62, the output of which is fed to motor'26'overconductor 563. The motor 26 thus will vary the audio attenuator S in thesame manner as the attenuator 11 was varied during the rst rehearsal,since the attenuators 8 and 11 are identical and the potentiometers 27and 34 `are identical.

VDuringV this automatic rerecording operation, a new control track isrecorded by record-reproduce head 55 on control track nlm 5S.Also'during this rerecording operation, manual changes may be made inthe amplitude of the audio signal by manipulation of the knob 31 ofattenuator 1l. Thus, the @new control track may be a combination of theoriginal manipulation of attenuator 11 plus any changes made by thesubsequent manual manipulation of attenuator 11. Thus, the control track5S will contain the new variations in amplitude of the signal.

If this second or last rehearsal was satisfactory, the switch S2 may beclosed and the control track on film 53 reproduced to control theamplitude level of the signal being recorded by recorder 15. VDuringthis operation, the switch 42 is in its first or upper position shown inthe drawing whereby record-reproduce head 55 is connected over conductor54:- and swinger 45 to the signal control amplilier 62 and thus to motor26. Since there is no control track on film 58 during the firstrehearsal, the motor 26 will not be energized. During any subsequentautomatically controlled recording operation, additional variationsfmaybe made by manually adjusting the attenuator Ill, a new control trackbeing recorded on either nlm 56' or film 58. If no control track is tobe recorded, switch 53 may be opened. Y The above system, therefore,requires a minimum of equipment for obtaining an automatic rerecordingopera-Y tion and has the advantage of utilizing standard audioattenuators now found on mixing consoles. The additional equipmentrequired includes the potentiometers 27 and 34 and the motor 26. Thus,such a system provides not only automatic control but manual controlduring the automatic control which does not interfere in any manner withthe automatic operation of the system.

l claim:

l. In a sound rerecording system, the combination of a source ofsignals, a transmission circuit for signals from said source, 'saidtransmission circuit including a pair of signal amplitude attenuatorsconnected together, a pair of voltage varying devices, each device beingmechanically connected to a separate one of said attenuators, a sourceof control current, said voltage varying devices being connectedtogether and to said source of control current, said voltage varyingdevices being adjustable in accordance with the adjustments of saidattenuators, means for recording variations in said control currentproduced by yadjustments of said voltage varying devices, and means forrecording said signals as varied by said attenuators.

2. A sound rerecording system in accordance with claim l in which saidattenuators are connected in series and said voltage varying devices`are connected in series.

3. A sound rerecording system in accordance with claim l in which saidirst-mentioned means'includes a y'2,8465515 A Y t,

. 'il-` recording system connected to said source of control current andsaid voltage varying devices.

4. A sound rerecording `system in accordance with Claim l in which amotor is provided for varying one of said attenuators and one of saidvoltage varying devices and manually operable means are provided forvarying the other of said attenuators and voltage varying devices.

5. A sound rerecording system in accordance with claim 4 in which saidmotor is connected tov said iirstmentioned means for actuating Vtheattenuator connected thereto, the recorded control current energizingsaid motor.

6. An Vautomatic rerecording system comprising a source of audiosignals, a source of control track signals,

a recorder of said audio signals', a recorder of said control signals,means for connecting said source of audio signals to said recorderthereof, said means including a pair of attenuators for varying thelevel of said audio signals, means for connecting said source of controltrack signals to the recorder thereof, said means including a pair ofpotentiometers for varying the level of said control track signals, eachone of said potentiometers being me chanically connected to a separateone of said attenuators, adjustment of one of said attenuatorssimutaneously adjusting its connected potentiometers, fand individualmeans for adjusting each of said attenuators.

7. An automatic rerecording system in accordance with claim 6 in whichone of said individual means is an manually operated element and saidother individual means is a motor energized from a recorded controltrack signaL 8. An automatic rerecording system in accordance withvclaim 7 in which said recorder for said control signals inf cludes acontrol track film on which said control track signals are recorded,means for connecting said recorder to said motor, a second control trackfilm, and means for recording said control track signals on said secondfilm during the connection of said recorder to said motor.

9. An automatic rerecording system in accordance with claim 8 in whichsaid recorder of said audio signals is adapted to simultaneously recorda plurality of audio signals'.

l0. In a sound rerecording system for a source of signals, thecombination of a transmission circuit for signals from said source, saidtransmission circuit including sigf nal amplitude attenuating means, apair of voltage varying devices', one of which is mechanically connectedto said signal amplitude attenuating means, a source of control current,at least one of said voltage varying 'devices being connected'to saidsource of control current, one of said voltage varying devices beingadjustable in accordance with the adjustment of said signal amplitudeattenuat` ing means, means for recording variations in said con-V trolcurrent produced by adjustments of said one voltage varying deviceconnected to said signal amplitude attenuatmg means, and motor means foractuating said signal amplitude attenuating means and said one voltagevarying device.y

ll. A sound recording system in accordanceV with claim l0 in whichmanually actuated means is provided for actuating said other Voltagevarying device.

No references cited.

